vfs: remove DCACHE_NEED_LOOKUP

The code that relied on that flag was ripped out of btrfs quite some time ago, and never added back. Josef indicated that he was going to take a different approach to the problem in btrfs, and that we could just eliminate this flag. Cc: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

vfs: remove DCACHE_NEED_LOOKUP
The code that relied on that flag was ripped out of btrfs quite some time ago, and never added back. Josef indicated that he was going to take a different approach to the problem in btrfs, and that we could just eliminate this flag. Cc: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Jeff Layton · Al Viro
1 parent 741b7c3f77
Showing 4 changed files with 3 additions and 65 deletions Side-by-side Diff
fs/btrfs/inode.c
fs/dcache.c
fs/namei.c
include/linux/dcache.h
@@ -4262,16 +4262,7 @@
 	if (dentry->d_name.len > BTRFS_NAME_LEN)
 		return ERR_PTR(-ENAMETOOLONG);
  
-	if (unlikely(d_need_lookup(dentry))) {
-		memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
-		kfree(dentry->d_fsdata);
-		dentry->d_fsdata = NULL;
-		/* This thing is hashed, drop it for now */
-		d_drop(dentry);
-	} else {
-		ret = btrfs_inode_by_name(dir, dentry, &location);
-	}
-
+	ret = btrfs_inode_by_name(dir, dentry, &location);
 	if (ret < 0)
 		return ERR_PTR(ret);
  
@@ -4341,11 +4332,6 @@
 	struct dentry *ret;
  
 	ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
-	if (unlikely(d_need_lookup(dentry))) {
-		spin_lock(&dentry->d_lock);
-		dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
-		spin_unlock(&dentry->d_lock);
-	}
 	return ret;
 }
  
@@ -455,24 +455,6 @@
 EXPORT_SYMBOL(d_drop);
  
 /*
- * d_clear_need_lookup - drop a dentry from cache and clear the need lookup flag
- * @dentry: dentry to drop
- *
- * This is called when we do a lookup on a placeholder dentry that needed to be
- * looked up.  The dentry should have been hashed in order for it to be found by
- * the lookup code, but now needs to be unhashed while we do the actual lookup
- * and clear the DCACHE_NEED_LOOKUP flag.
- */
-void d_clear_need_lookup(struct dentry *dentry)
-{
-	spin_lock(&dentry->d_lock);
-	__d_drop(dentry);
-	dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
-	spin_unlock(&dentry->d_lock);
-}
-EXPORT_SYMBOL(d_clear_need_lookup);
-
-/*
  * Finish off a dentry we've decided to kill.
  * dentry->d_lock must be held, returns with it unlocked.
  * If ref is non-zero, then decrement the refcount too.
@@ -565,13 +547,7 @@
  	if (d_unhashed(dentry))
 		goto kill_it;
  
-	/*
-	 * If this dentry needs lookup, don't set the referenced flag so that it
-	 * is more likely to be cleaned up by the dcache shrinker in case of
-	 * memory pressure.
-	 */
-	if (!d_need_lookup(dentry))
-		dentry->d_flags |= DCACHE_REFERENCED;
+	dentry->d_flags |= DCACHE_REFERENCED;
 	dentry_lru_add(dentry);
  
 	dentry->d_count--;
@@ -1735,13 +1711,6 @@
 		iput(inode);
 		return found;
 	}
-
-	/*
-	 * We are going to instantiate this dentry, unhash it and clear the
-	 * lookup flag so we can do that.
-	 */
-	if (unlikely(d_need_lookup(found)))
-		d_clear_need_lookup(found);
  
 	/*
 	 * Negative dentry: instantiate it unless the inode is a directory and
@@ -1275,9 +1275,7 @@
 	*need_lookup = false;
 	dentry = d_lookup(dir, name);
 	if (dentry) {
-		if (d_need_lookup(dentry)) {
-			*need_lookup = true;
-		} else if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
+		if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
 			error = d_revalidate(dentry, flags);
 			if (unlikely(error <= 0)) {
 				if (error < 0) {
@@ -1383,8 +1381,6 @@
 			return -ECHILD;
 		nd->seq = seq;
  
-		if (unlikely(d_need_lookup(dentry)))
-			goto unlazy;
 		if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
 			status = d_revalidate(dentry, nd->flags);
 			if (unlikely(status <= 0)) {
@@ -1409,11 +1405,6 @@
  
 	if (unlikely(!dentry))
 		goto need_lookup;
-
-	if (unlikely(d_need_lookup(dentry))) {
-		dput(dentry);
-		goto need_lookup;
-	}
  
 	if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)
 		status = d_revalidate(dentry, nd->flags);
@@ -202,7 +202,6 @@
 #define DCACHE_MOUNTED		0x10000	/* is a mountpoint */
 #define DCACHE_NEED_AUTOMOUNT	0x20000	/* handle automount on this dir */
 #define DCACHE_MANAGE_TRANSIT	0x40000	/* manage transit from this dirent */
-#define DCACHE_NEED_LOOKUP	0x80000 /* dentry requires i_op->lookup */
 #define DCACHE_MANAGED_DENTRY \
 	(DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
  
@@ -407,13 +406,6 @@
 {
 	return dentry->d_flags & DCACHE_MOUNTED;
 }
-
-static inline bool d_need_lookup(struct dentry *dentry)
-{
-	return dentry->d_flags & DCACHE_NEED_LOOKUP;
-}
-
-extern void d_clear_need_lookup(struct dentry *dentry);
  
 extern int sysctl_vfs_cache_pressure;
...	...	@@ -4262,16 +4262,7 @@
4262	4262	if (dentry->d_name.len > BTRFS_NAME_LEN)
4263	4263	return ERR_PTR(-ENAMETOOLONG);
4264	4264
4265		- if (unlikely(d_need_lookup(dentry))) {
4266		- memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
4267		- kfree(dentry->d_fsdata);
4268		- dentry->d_fsdata = NULL;
4269		- /* This thing is hashed, drop it for now */
4270		- d_drop(dentry);
4271		- } else {
4272		- ret = btrfs_inode_by_name(dir, dentry, &location);
4273		- }
4274		-
	4265	+ ret = btrfs_inode_by_name(dir, dentry, &location);
4275	4266	if (ret < 0)
4276	4267	return ERR_PTR(ret);
4277	4268
...	...	@@ -4341,11 +4332,6 @@
4341	4332	struct dentry *ret;
4342	4333
4343	4334	ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4344		- if (unlikely(d_need_lookup(dentry))) {
4345		- spin_lock(&dentry->d_lock);
4346		- dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
4347		- spin_unlock(&dentry->d_lock);
4348		- }
4349	4335	return ret;
4350	4336	}
4351	4337
...	...	@@ -455,24 +455,6 @@
455	455	EXPORT_SYMBOL(d_drop);
456	456
457	457	/*
458		- * d_clear_need_lookup - drop a dentry from cache and clear the need lookup flag
459		- * @dentry: dentry to drop
460		- *
461		- * This is called when we do a lookup on a placeholder dentry that needed to be
462		- * looked up. The dentry should have been hashed in order for it to be found by
463		- * the lookup code, but now needs to be unhashed while we do the actual lookup
464		- * and clear the DCACHE_NEED_LOOKUP flag.
465		- */
466		-void d_clear_need_lookup(struct dentry *dentry)
467		-{
468		- spin_lock(&dentry->d_lock);
469		- __d_drop(dentry);
470		- dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
471		- spin_unlock(&dentry->d_lock);
472		-}
473		-EXPORT_SYMBOL(d_clear_need_lookup);
474		-
475		-/*
476	458	* Finish off a dentry we've decided to kill.
477	459	* dentry->d_lock must be held, returns with it unlocked.
478	460	* If ref is non-zero, then decrement the refcount too.
...	...	@@ -565,13 +547,7 @@
565	547	if (d_unhashed(dentry))
566	548	goto kill_it;
567	549
568		- /*
569		- * If this dentry needs lookup, don't set the referenced flag so that it
570		- * is more likely to be cleaned up by the dcache shrinker in case of
571		- * memory pressure.
572		- */
573		- if (!d_need_lookup(dentry))
574		- dentry->d_flags \|= DCACHE_REFERENCED;
	550	+ dentry->d_flags \|= DCACHE_REFERENCED;
575	551	dentry_lru_add(dentry);
576	552
577	553	dentry->d_count--;
...	...	@@ -1735,13 +1711,6 @@
1735	1711	iput(inode);
1736	1712	return found;
1737	1713	}
1738		-
1739		- /*
1740		- * We are going to instantiate this dentry, unhash it and clear the
1741		- * lookup flag so we can do that.
1742		- */
1743		- if (unlikely(d_need_lookup(found)))
1744		- d_clear_need_lookup(found);
1745	1714
1746	1715	/*
1747	1716	* Negative dentry: instantiate it unless the inode is a directory and
...	...	@@ -1275,9 +1275,7 @@
1275	1275	*need_lookup = false;
1276	1276	dentry = d_lookup(dir, name);
1277	1277	if (dentry) {
1278		- if (d_need_lookup(dentry)) {
1279		- *need_lookup = true;
1280		- } else if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
	1278	+ if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
1281	1279	error = d_revalidate(dentry, flags);
1282	1280	if (unlikely(error <= 0)) {
1283	1281	if (error < 0) {
...	...	@@ -1383,8 +1381,6 @@
1383	1381	return -ECHILD;
1384	1382	nd->seq = seq;
1385	1383
1386		- if (unlikely(d_need_lookup(dentry)))
1387		- goto unlazy;
1388	1384	if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
1389	1385	status = d_revalidate(dentry, nd->flags);
1390	1386	if (unlikely(status <= 0)) {
...	...	@@ -1409,11 +1405,6 @@
1409	1405
1410	1406	if (unlikely(!dentry))
1411	1407	goto need_lookup;
1412		-
1413		- if (unlikely(d_need_lookup(dentry))) {
1414		- dput(dentry);
1415		- goto need_lookup;
1416		- }
1417	1408
1418	1409	if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)
1419	1410	status = d_revalidate(dentry, nd->flags);
...	...	@@ -202,7 +202,6 @@
202	202	#define DCACHE_MOUNTED 0x10000 /* is a mountpoint */
203	203	#define DCACHE_NEED_AUTOMOUNT 0x20000 /* handle automount on this dir */
204	204	#define DCACHE_MANAGE_TRANSIT 0x40000 /* manage transit from this dirent */
205		-#define DCACHE_NEED_LOOKUP 0x80000 /* dentry requires i_op->lookup */
206	205	#define DCACHE_MANAGED_DENTRY \
207	206	(DCACHE_MOUNTED\|DCACHE_NEED_AUTOMOUNT\|DCACHE_MANAGE_TRANSIT)
208	207
...	...	@@ -407,13 +406,6 @@
407	406	{
408	407	return dentry->d_flags & DCACHE_MOUNTED;
409	408	}
410		-
411		-static inline bool d_need_lookup(struct dentry *dentry)
412		-{
413		- return dentry->d_flags & DCACHE_NEED_LOOKUP;
414		-}
415		-
416		-extern void d_clear_need_lookup(struct dentry *dentry);
417	409
418	410	extern int sysctl_vfs_cache_pressure;
419	411